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CVE-2026-89568

Status: ReceivedUnscored—

In the Linux kernel, the following vulnerability has been resolved:

kho: fix size calculation in kho_preserved_memory_reserve()

kho_preserved_memory_reserve() calculates the size of a preservation by doing 1 << (order + PAGE_SHIFT). Since the '1' is a 32-bit integer, it can only be shifted by 31. That is, it will only work for preservations up to 2 GiB. Larger preservations will trigger undefined behaviour.

While preservations larger than 2 GiB can't be obtained via folios currently, they can be obtained via kho_preserve_pages().

For example, memblock reserve_mem uses kho_preserve_pages(). Reservations larger than 2 GiB are valid and will trigger this bug if properly aligned.

Read full descriptionShow less

Fix it by using 1UL for shifting.

CVSS

NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Linux — Linux KernelAI

References

Raw JSON (NVD)

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{
  "id": "CVE-2026-89568",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "fc33e4b44b2717feba2f6f07ce7943a96499c9ec",
              "lessThan": "42a6f03cf352eb6e6dbeef95e75e686f4cdb9bd1",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "fc33e4b44b2717feba2f6f07ce7943a96499c9ec",
              "lessThan": "3a0b8fa2eb36afc88b62a95f33f0c77c71fa5ded",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "kernel/liveupdate/kexec_handover.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.16",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "kernel/liveupdate/kexec_handover.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:19:40.810",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3a0b8fa2eb36afc88b62a95f33f0c77c71fa5ded",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/42a6f03cf352eb6e6dbeef95e75e686f4cdb9bd1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkho: fix size calculation in kho_preserved_memory_reserve()\n\nkho_preserved_memory_reserve() calculates the size of a preservation by\ndoing 1 << (order + PAGE_SHIFT). Since the '1' is a 32-bit integer, it\ncan only be shifted by 31. That is, it will only work for preservations\nup to 2 GiB. Larger preservations will trigger undefined behaviour.\n\nWhile preservations larger than 2 GiB can't be obtained via folios\ncurrently, they can be obtained via kho_preserve_pages().\n\nFor example, memblock reserve_mem uses kho_preserve_pages().\nReservations larger than 2 GiB are valid and will trigger this bug if\nproperly aligned.\n\nFix it by using 1UL for shifting."
    }
  ],
  "lastModified": "2026-09-11T20:19:40.810",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}